1. Field of the Invention
This invention pertains generally to tool bar equipped rotary hoes and more particularly to hoes wherein each hoe wheel of a plurality of hoe wheels is individually biased downwardly toward the soil.
2. Description of the Prior Art
Conventional rotary hoes today, utilize a tool bar which is usually connected to the tractor by a three point hitch. The tool bar supports a rearward, parallel extending pivot shaft which supports a plurality of abutting pivotally mounted hoe wheel arms. Each arm has a hoe wheel rotatably mounted on its lower portion and an upper stop that abuts the tool bar when raised via a helical torsion spring that extends between the arm and the tool bar. Most commonly long and short arms are interspersed along the pivot shaft with varying stop structure to provide two longitudinally spaced rows of wheels which resist the tendency of the hoe wheels to carry trash along as they are drawn across the soil. The stops also properly position all of the hoe wheels and when the tool bar is lowered, the springs are equally deflected depending upon the amount of weight transferred thereto by the tractor hitch. Because of a spring per arm and the single wheel per arm, each wheel can follow the terrain regardless of obstacles without affecting the other. The above described rotary hoe is of light weight, easily handled by a tractor, and provides high speed cultivation of even narrow rows.
Due to the hoe wheel action and their close in location to the tool bar however, considerable soil is thrown into the air and falls on the area of the pivot shaft although a shield usually protects the operator. While the hub bearing of each arm is generally located adjacent the hub of another on the shaft to keep the hoe wheels operating in a substantially vertical plane, nevertheless the soil gets between the pivot shaft and each hub and the associated arm frequently freezes on the shaft in an upraised position with the spring unable to return same to the stop position when the tool bar is raised. Hence when the tool bar is again lowered, all of the hoe wheels are not similarly positioned and the raised hoe wheel may not contact the soil or may be above the depth of the others. Thus, the terrain covered by the rotary hoe is not uniformly hoed. Also, the hoe wheel may freeze in a high raised position after encountering an obstacle. Hereto, effective hoeing is not possible. The operator has to then stop the hoeing process to free the arm on the shaft and perhaps disassemble same so that the spring can again control the arm and hoe wheel. This increases the down time of the hoe.